Probably the biggest cause of 911 misdials is the proverbial "butt dial" where users accidentally hit the speed dial sequence for 911 on their mobile phone while in their pocket. Enterprise PBXs are also a common source of calls to 911 when the user didn't intentionally plan on making that call. The problem here is that in many cases the PBX doesn't report station level caller ID, or if it does, in many cases the carrier will overwrite that information with the main billing telephone number.

For users that have implemented an E 911 remediation plan in their building, part of that plan will include on-site notification. And even though a generic number may be reported to the 911 center, detailed information on the station placing the call is available internally. Obviously, this information is critical when someone actually has an emergency, as you know exactly where they're located and can provide immediate help. But it also provides information on 911 misdial events if programmed properly in the PBX.

Over the years I've had several calls from users that were frustrated about the Police Department knocking on their front door claiming a 911 call came from the building, yet no one in the building would admit to making that mistake. On-site notification is the best evidence in this case in remediating the problem. But it might not be an individual that's actually making the call. Many times fax machines will have the destination number programmed incorrectly, and they will be making the 911 call. Not only is this extremely annoying to the Police Department as the fax machine tries over and over and over to connect with the far end, quite often it's very difficult to locate the device without going on a physical search. Even then, when that misdials number is stored in the memory buffer, it can become extremely difficult to locate within a large enterprise.

Common causes of misdials:Area codes that start with "91"People down 91, then glanced at the number and continue dialing 1+ area code and number. The PBX sees 911 201-555-1212, but processes the emergency call after the first three digits.

Central office codes that start with "91"Users dial 91 and then get an extra one by mistake

Dialing Indiaspecifically, the country code for calling India is 91, and the city code for calling New Delhi is 11. If the caller forgets to dial the international dialing code prefix "011," the digits "9111" would be transmitted. Again, as soon as the telephone system receives 911 the remaining digits are ignored in the call is routed to the PSAP.

Dialing Nuremberg Germanythis one is easy the city code for dialing Nuremberg is 911. Enough said.

In a MLTS/PBX system there are two parts of the problem that need to be addressed. The first is fairly simple, and it involves something you should already have programmed in your system, and that's crisis alert on-site notification. This is an internal indicator that provides up to 10 stations and alert when an emergency call is placed, and the extension number and name of the station placing the call is displayed to the station as well as an audible alert on a programmed button.

Most of our third-party dev connect solutions also offer this functionality at much greater detail, and can include screen pop alerts, SMS messages or even emails. The solutions take the basic information delivered through crisis alert or on-site notification and enhance it with additional detail such as distinguishing between multiple stations with abridged appearance number. But this is only half of the solution, and a little bit of programming needs to happen to catch the true misdials.

On the CS 1000, programming is fairly simple and includes an actual misdial feature. This feature is either on or off and looks for additional digits being dialed after any emergency service directory number (ESDN) is processed. The options are to either allow or ignore the last number in the ESDN and how long the system should wait after recognizing the ESDN for additional digits.

For example, if you allow the last number to repeat, then 911 and 9111 would be considered an emergency call. But 9112 through 9119 would be considered a misdial. If you chose to not allow the last number to repeat, then 911 plus any digit (including one) would be considered a misdials. The default timer is four seconds, which seems to work in every instance, however it is adjustable if you need it to be.

The last option is how you want the misdialed calls to terminate. Your choices are busy signal, intercept, attendant console or recorded announcement device. I recommend a RAN so that you can play an announcement to the caller advising that they may have just misdialed 911, and if it's an actual emergency, to hang up and dial again.

With this programming in place, any 911 call or 911 misdial will trigger specific alerting that can be acted upon. A special indication is presented for 911 misdials, and if supported in the third-party application, will be included in the on-screen displays.

For users that have the CM, similar logic will apply, and can be programmed as follows:

In addition to having 911 in your ARS tables flagged as crss-alrt for crisis alert reporting, programming additional entries of 9111 through 9119 and terminate them locally to an announcement that tells the user that if they were trying to reach 911 that they have misdialed.

MAKE SURE YOU MARK THESE ENTRIES AS CRSS-ALRT FOR CRISIS ALERT REPORTING SO THAT ON-SITE PERSONNEL CAN INVESTIGATE AND MAKE SURE THIS WAS NOT AN ACTUAL 911 CALL ATTEMPT!

Make sure you run your game plan by your internal risk management folks, as well as HR before you start, and it's not a bad idea to talk to your local PSAP as well. If you haven't done so before, it's a great time to start building a relationship with these folks, and getting their input on what your plan is.

Regardless of what you do to allow for, or deny, emergency calling in your PBX, make sure that once you have completed your programming, you test your configuration to make sure that you haven't accidentally blocked any valid 911 calls. Of course before you test, you need to find the local NONEMERGENCY number for your local police station, and coordinate testing activities with whatever their local policy dictates.

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Mark J. Fletcher, ENP (Fletch) manages Product Strategy for Public Safety Solutions at Avaya.
Fletch is responsible for ...
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Mark J. Fletcher, ENP (Fletch) manages Product Strategy for Public Safety Solutions at Avaya.
Fletch is responsible for ensuring the roadmap and strategy of Next Generation Emergency Services in both the public and private sectors. With nearly 3 decades of experience in telecom, he has built and managed some of the world’s largest private networks. Mark is regularly called upon to provide insights to legislators and the industry to drive forward both innovation and compliance in Enterprise Emergency Services.
This weekly CONNECTED Blog will explore the challenges faced by IT Administrators today who are expanding user connectivity, while maintaining a safe environment for these devices to call 911 in times of crisis.
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